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What exactly does a relationship in a relational database mean? In view of this problem, this article gives the corresponding analysis and answers, hoping to help more friends who want to solve this problem to find a more simple and feasible way.

The so-called relationship in the relational database management system means that the data model is a two-dimensional table format that satisfies certain conditions.

It has the advantages of object-oriented database management system: it is easy to express all kinds of complex relationships between objects, and the association between methods and data is realized through the encapsulation of objects in the database.

The identity of the elephant, the polymorphism of the object and night coverage are all supported.

Compared with the object database management system, we can make use of the mature technology and research results of the relational database management system.

Unified, it can better meet the needs of the application.

Class definition and manipulation. Object-oriented database languages can manipulate classes, including defining, generating, accessing, modifying, and revoking classes. The definition of the class includes defining the properties and operations of the class.

Characteristics, inheritance and constraints, etc.

Extended data

Representative data management systems are: Oracle, Microsoft SQL Server, Access, MySQL and PostgreSQL. Usually, database administrators use data.

Library management system to create a database system.

Database management system not only has the function of user-oriented, but also has the function of system-oriented.

Due to the lack of unified standards for DBMS, their performance, functions and many other aspects vary with the system. In general, the function of large-scale system is stronger than that of small-scale system.

The performance of the same kind of system is also different. In general, the main features of DBMS include:

Database definition function. DBMS provides the corresponding data definition language to define the database structure, which is the framework for describing the database and is saved in the data dictionary. The data dictionary is

The basic basis for DBMS to access and manage data.

Data access function. DBMS provides data manipulation language to achieve the basic access to database data: retrieval, insertion, modification and deletion.

This is the end of the relationship explanation in the relational database. I hope the above content can be helpful to everyone and learn more knowledge. If you think the article is good, you can share it for more people to see.

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